School of Biosciences

Illuminating cells with synthetic biology

10 May 2013

Writing with bacteria: using lasers to switch on protein activity in individual bacterial cells

A multidisciplinary Cardiff team led by senior lecturer Dr Dafydd Jones (School of Biosciences) have generated a simple system to control protein activity purely by shining light on the cells. The work performed by PhD student Sam Reddington with support from Pete Watson (Biosciences), Pierre Rizkallah (Medicine) and Eric Tippmann (Chemistry) lays the foundation for a broader use of this new technology in biology and beyond.

In order to develop this simple control system, the group reprogrammed one of the most fundamental aspects of biology: the genetic code. By altering the way that one aspect of the code of life is interpreted whilst introducing a simple derivative of an existing amino acid, the building blocks of proteins, the team were able to introduce light sensitive properties into a protein. This new chemistry using the light sensitive amino acid has not previously been sampled in nature, but can be incorporated at defined positions in any chosen target protein using genetic engineering. The chosen protein for these experiments was one of the most important proteins in experiment cell biology research: Green Fluorescent Protein (GFP).

The new “non-natural” versions of GFP produced in these experiments display a number of useful characteristics in response to light, including the ability to turn on or off the proteins activity. The team used high precision laser microscopy to adeptly demonstrate the light sensitive activation of the proteins activity, proving it is possible to write at the microscopic level by activating the protein in individual bacteria cells.

Dr Jones said “This is an important breakthrough in the use of light to control proteins and biological processes. There is currently a great deal of interest in using light to control biological processes as it is non-toxic and can be applied with high spatial and temporal precision”.

The work published in the leading chemistry journal Angewandte Chemie also provides a detailed molecular basis for the action of light on GFP. Dr Jones said “The molecular insights unearthed during this work have greatly added to our understanding of the how light controls the activity of GFP opening up the approach for use with other proteins and thus becoming a more general application.”